Abstract: A device for measuring of urine production of a patient carrying a urine catheter, the device comprising a replaceable self-emptying chamber (120), provided with a siphon for self emptying when the burette becomes filled up to a predetermined volume, the self-emptying chamber further comprises an inlet and an outlet for the urine whose volume is to be measured, further, the device comprises a base unit (105) provided with attachment organs for removably attaching the self-emptying chamber (120) to the base unit, which station having measurement organs for sensing the level of urine in the self-emptying chamber and for keeping track of number of self-emptyings.

Abstract: The present invention relates to a method for monitoring the operation of a medication delivery device. In particular, the present invention relates to a method comprising the steps of arranging an electronic module in the vicinity of the medication delivery device, detecting, using the electronic module, measurable signals generated in response to an action occurring within the associated medication delivery device, and storing, using storage means of the electronic module, information associated with or representing the measured signals. The present invention further relates to an electronic module capable of performing the above-mentioned method.

Abstract: A method for fire detection in enclosed environments (1) subject to explosion protection regulations out of which an air-dust mixture is filtered while the concentration of dust of the air-dust mixture is lowered to under the explosion limit by a filter (2) and the aspirated air-dust mixture is checked for burning characteristics and if appropriate a fire alarm is triggered, in which the function of the filter (2) is monitored, the fire detection is carried out by use of an aspirating smoke detector system (7) not approved for use in potentially explosive areas but instead is deployed outside the ex-zone and if the filter (2) is destroyed a signal processing unit (15, 15.1) of a malfunction monitoring sensor (14) generates a signal which initiates a subsequent action preventing aspirated air-dust mixture with an elevated concentration of dust from entering the aspirating smoke detector system (7).

Abstract: An improved pump, reservoir and reservoir piston are provided for controlled delivery of fluids. A motor is operably coupled to a drive member, such as a drive screw, which is adapted to advance a plunger slide in response to operation of the motor. The plunger slide is removably coupled to the piston. A method, system, and an article of manufacture for automatically detecting an occlusion in a medication infusion pump is provided. The electrical current to an infusion pump is measured. Based on a series of measurements of one or more variables, the infusion pump detects whether there is an occlusion in the system.

Abstract: A flowmeter method and system. In an implementation, a signal is received from a flowmeter and a value is determined based on the signal. The value is compared to a threshold. A heartbeat value is provided when the value is greater than a threshold value. In some implementations, a flow rate of a fluid is based on the heartbeat value. In some implementations, the heartbeat value is monitored and an alarm is selectively generated based on the monitoring.

Abstract: The present invention relates to a system for determining particle transmittance Tx of a filter for use with a particle detection system to provide a filter warning for aspirated particle detection systems by detecting a level of first particles having a size indicative of smoke particles and which pass through the detection system; determining an integrated smoke hours value by integrating the detected level of first particles over time; estimating the smoke particle transmittance Tx of the filter by applying a predetermined weighting operation to the integrated smoke hours value. An empirical measure of a filter's particle transmittance Tx, due to at least first particles having a size indicative of smoke particles may be achieved by way of integrating a level of such first particles passing through a particle detection system over time to determine the proportion of smoke particles arrested by a filter, “integrated smoke hours”.

Abstract: The disclosed invention is a method of detecting flow conditions in a fluid supply system and is particularly useful for detecting flow in a toilet system. The flow detection method uses a device comprising a processor associated with a flow sensor and a memory which stores predefined flow criteria. When the processor detects flow through the fluid supply system, the processor uses the flow criteria to characterize the detected flow. If such flow complies with predefined flow conditions, a flow event is noted and an alert is issued. Such alert is configured according to predefined alert-criteria stored in a memory.

Abstract: Material passing through a piping is laced with Radio Frequency Identification (RFID) tags. As the RFID tags pass an RFID sensor, which is either adjacent to or within the piping, a flow-rate of the material is determined by counting the rate at which the RFID tags pass the RFID sensor.

Abstract: A water meter with an emergency shutdown is a dual purpose water meter, which records the accumulated water consumption of individual runs as any regular water meter, and detects water leakage or uncontrolled flow by comparing each single continuous run in non-equal batches with a set target quantity. The water meter shuts down the water flow if a single continuous run reach that target. The water meter is adaptable to any type of water meter or method of recording, turbine, vertical turbine, positive displacement, multiple jet, propeller, or magnetic or electronic flow measuring.

Abstract: A method and system for monitoring a gas turbine engine (20) to predict maintenance requirements. Particles suspended in a gas flow (24, 32) of the engine (20) are monitored and quantified to predict a particle accumulation rate. Monitoring may be done using particle flow sensors (61-63) in a diverted portion (33) of the working gas flow (24), such as in the cooling gas flow (32). Particle sampling (S1-S3) may be done to determine particle size and composition distributions. Particle mass flow rates may then be continuously monitored per engine operating condition, and compared to predetermined values such as a normal upper limit per engine operating condition. An integrated particle mass flow may be used in conjunction with an instantaneous mass flow rate to predict a maintenance requirement. Multiple locations (L1-L3) may be monitored to recognize a maintenance requirement by flow section or component.

Abstract: The present invention relates to a system for determining particle transmittance Tx of a filter for use with a particle detection system to provide a filter warning for aspirated particle detection systems by detecting a level of first particles having a size indicative of smoke particles and which pass through the detection system; determining an integrated smoke hours value by integrating the detected level of first particles over time; estimating the smoke particle transmittance Tx of the filter by applying a predetermined weighting operation to the integrated smoke hours value. An empirical measure of a filter's particle transmittance Tx, due to at least first particles having a size indicative of smoke particles may be achieved by way of integrating a level of such first particles passing through a particle detection system over time to determine the proportion of smoke particles arrested by a filter, “integrated smoke hours”.

Abstract: A cathodic protection device having a sacrificial anode that is intended to wear out due to corrosion and that is electrically connected to a structure to be protected against corrosion. The cathodic protection device of the present invention further includes an indication device configured to detect and indicate the wear of the sacrificial anode wirelessly, without the use of cables.

Abstract: The present invention is related to a liquid blocking apparatus and a system thereof, wherein if the liquid contained in an IV bag or a liquid tank is oozed out completely, the flow of liquid is blocked, the alarm lamp is turned on, the alarm sound is generated, and then the supply of liquid is maintained for a predetermined time.

Abstract: Surveillance system and surveillance method for detecting intruders. An image-pickup unit takes an image of a predetermined area, a person detection unit detects, on the basis of the taken image, information concerning people pictured in the image, radio terminal units are held and carried by people, radio reception units receive signals transmitted by radio from the radio terminal units present in the predetermined area, a terminal detection unit detects information concerning the radio terminal units on the basis of the received signals and an intruder decision unit detects information concerning an intruder on the basis of the information concerning the detected persons and the information detected in connection with the radio terminal units.

Abstract: To provide a fault-tolerant architecture to supply electrical operating power in fluid flow measurement applications, apparatus and associated systems, computer program products, and methods include an intelligent power module with redundant and electrically independent battery strings to supply regulated voltage to electronic fluid flow measurement data processing circuitry. In a preferred implementation, the intelligent power module transmits operating power and battery status information over a two wire interface. Circuitry may encode information about the status of individual battery strings in a DC supply voltage. The fluid meter processing circuitry operates from the DC supply voltage and decodes the battery status information. Preferred embodiments may also include a switched-mode power supply capable of extracting substantially all available stored energy capacity from each of the battery strings, each of which is electrically isolated by a unidirectional current circuit.

Abstract: A pressure detector for detecting a high side pressure from a high pressure side impulse line and a low side pressure from a low pressure side impulse line includes a high side pressure variance calculating section for calculating a high side pressure variance from a high side pressure fluctuation calculated from a high side pressure signal, a low side pressure variance calculating section for calculating a low side pressure variance from a low side pressure fluctuation calculated from a low side pressure signal, a rate calculating section for calculating a variable according to a ratio of the high side pressure variance to the low side pressure variance, and a determining section for determining blockage of the high pressure side impulse line or blockage of the low pressure side impulse line based on a value of the variable.

Abstract: A safety shutdown system is provided for use with a fluid delivery system, such as used on a delivery vehicle. The safety shutdown system includes a plurality of sensors for sensing characteristics of a fluid delivery system. A controller includes a query timer function initiated in response to the sensed characteristic of the fluid delivery system and/or in response to activation of selected vehicle functions. The operator may repeatedly reset the query timer before it times out by pressing a button on a wireless transmitter. If the timer times out, however, the controller automatically shuts off a vehicle engine and/or closes a valve to prevent further fluid delivery.

Abstract: A flow verification sensor apparatus (30) is used with a constant volume pump (11) that pumps a liquid product (13) from a container (12). A plummet (32) is positioned in a flow tube (31). A sensor (33) is positioned upward from the lower end of the flow tube (31). A timer (34) measures the length of time for the plummet (32) to move from a first position to a second position after activation of the pump (11). Suitable alarms (50) are operated to indicate low flow or out of product conditions.

Abstract: A system comprises a pressurized container configured to hold a pressurized gas and to supply controlled amounts of the pressurized gas to the system as required. The system also includes a sensor that includes a wireless transmitter. The sensor is configured to sense the pressure in the pressurized container and to periodically transmit, using the wireless transmitter, information related to the pressure in the pressurized container. The system also includes a control unit that includes a wireless receiver configured to receive the information transmitted by the sensor. The control unit is further configured to predict based on the received information when the pressure in the pressurized container will reach a predetermined threshold.

Abstract: A method of signaling for a change of an air filter of a vehicle air conditioning system is disclosed. The present invention uses a sensor installed in a conventional air conditioner and the appropriate time for changing the air filter is determined by checking compressor operation when a degree of airflow is decreased during air conditioner operation.

Abstract: A software driven, solid state controlled, electro-mechanically operated system to monitor volatile liquid fuel or other hazardous liquids and provide emergency shut-off if the delivery system is ruptured. A computer receives input from transducers monitoring the flow rate of the liquid through the line and a pressure sensor insures the system is prepared to function. The monitoring apparatus presets a condition based on current environmental conditions. Measuring the flow rate provides input to software that validates all other entries. Delivery quantities allowing point of delivery control to vary the delivery quantity to individual locations. The software options are: Preset conditions; Owner/operator input via external computer for loading delivery and trip instructions; Instructional output on LCD screen to driver on customer information and scheduling; Data download to owner/operator on billing information, driver daily activities and volume of propane remaining in vehicle.

Abstract: The present invention provides a device, system, and method for detecting and measuring the bi-directional flow of a fluid through a fluid meter, such as a household or business water meter. In one device embodiment the invention comprises a logical switch collar (12) disposed over an analog fluid meter (14) having a sweep-hand (18) with a magnet (16) coupled thereto. In operation, the logical switch collar (12) consists of at least two magnetic switches that are triggered to open or close in response to the rotational movement of the sweep-hand (18) as fluid flows through a fluid meter (14) in both the forward and reverse directions. These switching events are detected and recording by an electronic module (19). Advantageously, the present invention accurately monitors and records fluid consumption at predetermined intervals when the fluid flows through the meter in either direction (14).

Abstract: A water damage protection system and method of preventing water damage for domestic water supply systems is provided. The system comprises a control valve, a sensing device, and a controller. The control valve is bias toward an open position to allow fluid flow therethrough. The control valve is moveable to a closed position upon actuation thereby preventing fluid flow through the conduit. The sensing device detects fluid flow through the fluid conduit. The sensing device sends a fluid flow signal upon detection of fluid flow. The controller receives the fluid flow signal from the sensing device. The controller actuates the control valve when the fluid flow signal occurs continuously for a predetermined length of time and the control valve moves to a closed position.

Abstract: An apparatus for monitoring a fluid system particularly suited for use with high pressure liquid chromatography systems. The apparatus monitors seal leakage as well as the general wellness of the apparatus and can thus be used to provide preventive maintenance feedback. The apparatus includes a liquid chamber, a wash chamber, a reservoir, a supply pump, a return line, and a detector. The liquid chamber includes a seal for sealing a fluid within the liquid chamber. The wash chamber is located adjacent the seal. The reservoir supplies a wash solution to the wash chamber. The supply pump supplies a unidirectional flow of wash solution from the reservoir to the wash chamber. The return line conveys a return flow from the wash chamber to the reservoir, in which the return flow includes any leakage of the fluid from the liquid chamber into the wash chamber and the portion of the wash solution that returns from the wash chamber to the reservoir.

Abstract: An apparatus for monitoring a fluid system particularly suited for use with high pressure liquid chromatography systems. The apparatus monitors seal leakage as well as the general wellness of the apparatus and can thus be used to provide preventive maintenance feedback. The apparatus includes a liquid chamber, a wash chamber, a reservoir, a supply pump, a return line, and a detector. The liquid chamber includes a seal for sealing a fluid within the liquid chamber. The wash chamber is located adjacent the seal. The reservoir supplies a wash solution to the wash chamber. The supply pump supplies a unidirectional flow of wash solution from the reservoir to the wash chamber. The return line conveys a return flow from the wash chamber to the reservoir, in which the return flow includes any leakage of the fluid from the liquid chamber into the wash chamber and the portion of the wash solution that returns from the wash chamber to the reservoir.

Abstract: An electronic system for monitoring the condition of the filter in an HVAC unit includes a controller which issues at least one command to a circuit for the motor of the fan producing airflow through the filter. The command to the driver circuit is associated with a desired run speed for the fan. The controller is operative to compute the speed of the fan following issuance of the command to the motor drive circuit. This computed speed is compared to a predetermined fan speed that would normally occur when the filter is dirty. The electronic system is operative to generate a warning in the event that the computed fan speed does not compare favorably with the predetermined fan speed.

Abstract: A monitor, shutoff control, and alarm for use with an inlet water supply obtained from a municipal water supply to prevent excessive usage of water due to leakage or human error, that includes a measuring means and shutoff valve connected to the inlet supply, a processor that includes a program for setting threshold values of water volume per unit time anticipated by the particular household, which, when exceeded, will set off an audio alarm or will activate a telephone dialer to call a predetermined number if no one is at home. The system is programmed in volume increments of time, such as hours, days, or weeks, to accommodate systems that include sprinklers which may require some volume of water over a short period of time. The system can be portable. It is easily installed and mounted in conventional water systems for homes, but can be individually adjusted based on the anticipated water usage of a particular household.

Abstract: A water flow monitoring system for determining the presence of leaks in plumbing pipes having water flowing through the pipes under high pressure includes a flow monitor which is mounted to the pipe for sensing the flow of water through the pipe. A controller composed of a timer and/or accumulated volume meter associated with the flow monitor, to determine when the flow has continued for a preselected period of time, and/or when the amount of water has exceeded a preselected accumulated volume threshold, and logic components responsive to changes in flow rate. Upon detection of flow for the preselected period of time, and/or preselected accumulated volume threshold, a valve is actuated to stop flow through the pipe.

Abstract: An apparatus for flow detection, measurement and control and method for use of same in a piping and/or fire sprinkler system. The apparatus combines a flow sensor for creating an electrical output proportional to flow through therethrough with a bypass means for allowing flow through an alternate flow path where a primary flow path is insufficient to supply the demand. The apparatus includes a moving orifice plate, which is displaced by flow through the sensor and creates an electronic output by the interaction of a moving magnet moving in tandem with the orifice plate with a normally closed Reed switch on an exterior surface of the sensor, which is opened when the magnet is displaced into sufficiently close proximity to the Reed switch. The apparatus can also be adapted to serve as a double check valve. A moving check is added with a sealing means thereon for providing one check, and sealing means on the orifice plate are provided to serve as a second check.

Abstract: A totalization meter system for a water treatment device, the device having an inlet aperture and an outlet aperture, and a channel for channeling water between the inlet and outlet apertures. A flow reactive device is positioned in the channel and is exposed to the flowing water, and a signal generating member is positioned on the flow reactive device. A switch is positioned proximately to the flow reactive device, and is sensitive to the proximity of the signal Generating member. The switch is able to communicate electric signals indicative of the motion of the signal generating member. A resettable processor having a Performance threshold programmed therein and an output device is included. The microcontroller is in electrical communication with the switch for receiving electrical signals from the switch. The switch is cap able of sensing the characteristics of the flow reactive device and communicates electrical signals representative of the characteristics to the microcontroller.

Abstract: A flow detector includes solid state delay circuitry coupled to a flow indicating device. In response to flow being indicated, the delay circuitry is enabled. After a preset delay interval, if flow is still being indicated, an output signal can be generated. The flow indicating device can be a two-state mechanical switch. A mode setting element can be used to configure the detector for different types of installations.

Abstract: A sensor system. The system comprises a binary sensor issuing a signal representative of a first or second condition; sampling circuitry, operatively connected to the binary sensor, for monitoring the number of transitions between the first and second conditions during a sampling period; integration circuitry for accumulating the sampled number of transitions over time; and signal generation circuitry for issuing an analog signal representative of the accumulated transitions.

Abstract: A flow detector includes solid state delay circuitry coupled to a flow indicating device. In response to flow being indicated, the delay circuitry is enabled. After a preset delay interval, if flow is still being indicated, electrical energy can be provided by a short circuit to an output device for the duration of indicated flow. The flow indicating device can be a two-state mechanical switch. A short circuit supplying switch can be implemented as a solid state or mechanical latching relay. The flow detector circuits can be used independently to provide local alarms. Alternately they can provide alarm indicating signals to a common alarm control panel.

Abstract: A multipurpose residential plumbing and fire sprinkler system or, more simply, a multipurpose piping system ("MPS") is a system for providing water to both domestic uses (e.g., showers, sinks, toilets) and to sprinklers for fire protection. The invention provides an apparatus and method for alarming when one or more sprinklers connected to the MPS are activated by a fire. The invention uses a water flow detector. In particular, the invention provides an apparatus and method for distinguishing typical domestic water flow from the flow caused by one or more sprinkler heads.

Abstract: A method and system for monitoring integrity of a filter (25) of a smoke or fire detector system. The system has a detector chamber (14) into which light is passed from a light source incorporated into a light source control circuit (10). Scattered light is detected by a light scatter detector (12). Controller circuit (16) receives signal from the detector (12) and makes a cumulative count over time of the number of dust particles detected.

Abstract: A method and apparatus for detecting electrostatic discharge events is disclosed in which the electrostatic discharge indicator is "Electric Paper". The "Electric Paper" has a plurality of spheres having one hemisphere of one color and the other hemisphere of another color. The spheres rotate when an electric field is applied to them and are sensitive enough to respond to electrostatic discharge events. The "Electric Paper" may be pre-imaged so that a pattern indicating the state of the paper is visually ascertainable.

Abstract: In apparatus for counting a succession of falling liquid drops having teardrop shape, with a downwardly convex down side, the combination that includes a beam provider for providing a beam of electromagnetic radiation to sidewardly pass into the drop at its convex lower side, to be refracted within the drop to pass out of the drop at its convex lower side, and a beam detector located to detect the refracted beam that has passed sidewardly out of the drop at its convex lower side.

Abstract: A totalization meter system for a water treatment device, the device having an inlet aperture and an outlet aperture, and a channel for channeling water between the inlet and outlet apertures. A flow reactive device is positioned in the channel and is exposed to the flowing water, and a signal generating member is positioned on the flow reactive device. A switch is positioned proximately to the flow reactive device, and is sensitive to the proximity of the signal generating member. The switch is able to communicate electric signals indicative of the motion of the signal generating member. A resettable processor having a performance threshold programmed therein and an output device is included. The microcontroller is in electrical communication with the switch for receiving electrical signals from the switch. The switch is capable of sensing the characteristics of the flow reactive device and communicates electrical signals representative of the characteristics to the microcontroller.

Abstract: In flow measurement, a measurement signal essentially representing the instantaneous flow rate is determined with the aid of a flow transducer (2) in a flowmeter (1). In order to check whether the flowmeter measures correctly or not, the noise in the measurement signal from the transducer (2) is analyzed. To be more specific, one or more distribution values for the measurement signal are determined and compared with predetermined reference values that have been determined for operating conditions for which the flow transducer is intended. If this comparison reveals that the existing operating conditions differ from those for which the flowmeter is intended, a frequency spectrum for the measurement signal may be determined and compared with reference spectra that have been determined for various known operating conditions, thereby to identify the existing operating conditions. If these are identified, the function of the flowmeter may be corrected on line with the aid of predetermined correction data.

Abstract: A waterline leak detection and shutoff system comprising an in-line flap valve which includes a pivotal valve flap member having attached thereto a magnet and first magnetically responsive switch which switches states, when the magnet is moved from a first position to a second position by forces exerted by flowing water, to activate a counter, and a second magnetically responsive switch which switches states, when the magnet is moved from the second position to the first position as the water ceases flowing, to reset the count of the counter. The counter continuously counts while the magnet is in the second position wherein if the count reaches a predetermined time limit an alarm means and/or an in-line shutoff valve are activated.

Abstract: A protection system for hydraulic systems, mainly for pipes, faucets, valves, boilers, furnaces, etc.

Abstract: A faucet mounted water filtration system with a filter life monitor includes a filter housing with a flexible cap which deflects upon introduction of water into the housing. The deflection of the cap closes a switch on an electrical circuit which counts the time the water is flowing through the housing. Once a predetermined amount of time accumulates, the circuit generates a message to inform the user that the filter needs replacement. The invention further includes a selector switch on the electrical circuit for signaling the circuit to count one of two predetermined amounts of time prior to generating a message.

Abstract: A monitoring device for a drinking water purification system comprising a microprocessor that controls the overall operations of the monitoring system, a LCD indicating circuit that relates information to maintenance personnel, a detecting means that analyses related data for determining the condition and extents of clogging of the filtration elements, a warning means that produces verbal or musical sound for warning consumers about the clogged condition of the water filtration elements, and a power switching means that cuts off electricity supply to the water pump of the purification system. In operation, the filtration elements will be clogged by impurities after being used for a period of time. If the filtration elements are clogged, the monitoring device will make a sound to warn of such condition of the filtration elements and will eventually cut off the power supply to the pump for stopping water delivery if the clogged filtration elements are not replaced after a certain period of time.

Abstract: Apparatus and methods for monitoring a characteristic of fluid flow through a fluid dispenser that permit adverse flow conditions to be monitored, analyzed and displayed to an operator. The monitor samples either the static or firing pressure a predetermined number of times and calculates an average static and firing pressure over the sampling period. The average pressure values are compared to high and low warning and alarm limits and warning and alarm error codes are produced as a function thereof. In addition, individual sampled values are compared to the high and low warning and alarm limits and pressure values exceeding the limits during a sampling period are counted. Warning and alarm error codes are produced as a function of the counted values exceeding predetermined count values.

Abstract: A global positioning planter system for planting of seeds by a seed planter. A population control controls the seed planter. A global positioning system computer with digitized maps connects to the population control. The population control connects to the seeder for planting of seeds such as corn or beans or to seed drills for controlling the seed drill, and plants the seeds according to the population control which receives and transmits data with the global positioning system computer.

Abstract: A liquid flowed detection system is disclosed for monitoring continuous and discontinuous liquid flow in a fluid circuit. The system includes a holding device for maintaining a drip chamber so that its elongated axis generally lies in a vertical plane. A light emitter is oriented to transmit light along an optical path through the drip chamber and intersecting its elongated axis. A light detector located in the optical path opposite the light emitter, generates a signal representative of light received from the light emitter. A processor receives information from the detector and generates a control signal representative of a variability over time of the light detector signal. When the control signal drops below a predetermined level, a flow absence signal is generated which is then correlated to the system's pump velocity corresponding to a time interval (T). If the flow absence signal occurs continuously in a comparison time interval (T), a warning signal is generated.

Abstract: Apparatus and methods for monitoring a characteristic of fluid flow through a fluid dispenser that permit adverse flow conditions to be monitored, analyzed and displayed to an operator. The monitor samples either the static or firing pressure a predetermined number of times and calculates an average static and firing pressure over the sampling period. The average pressure values are compared to high and low warning and alarm limits and warning and alarm error codes are produced as a function thereof. In addition, individual sampled values are compared to the high and low warning and alarm limits and pressure values exceeding the limits during a sampling period are counted. Warning and alarm error codes are produced as a function of the counted values exceeding predetermined count values.

Abstract: A contamination monitoring system for monitoring contaminants in a liquid, comprising a first electrical conductivity sensor, a second electrical conductivity sensor, a filter and a pump, the filter being disposed between the first sensor and the second sensor, the pump being arranged to circulate the liquid, the first electrical conductivity sensor providing an indication of dissolved ionic contamination levels in the liquid prior to filtration of the liquid by the filter, the second electrical conductivity sensor providing an indication of dissolved ionic contamination levels in the liquid after filtering the liquid by the filter, the conductivity measured by the second electrical conductivity sensor being compared against a value to determine whether the liquid should be retained or discarded.

Abstract: A flow amount measuring and controlling apparatus which has a built-in gas meter can compute and control the flow amount used for each gas appliance by the estimation of the gas appliance generated in the flow variation from the change of the monetary flow amount passing through the gas meter, whereby, since the condition of the gas appliance can be correctly determined, the abnormal operation of the gas appliance can be detected so as to shut off the gas.

Abstract: A filter life indicator is described herein utilizing a constant flow channel and a flow actuated switch incorporating a reciprocating magnetic member to start a timer. Circuitry monitors this timer and actuates a visual or audible indicator when the filter needs to be replaced. The timer consists of a pulse generator, a scaling circuit, a counter, and a comparator. During flow pulses are counted and compared to a preset limit. And to accommodate filters having differing life expectancy, modules corresponding to each filter are installed to change the scaling circuit.